What causes an electron to jump energy levels?

An electron jumps energy levels when it absorbs or emits energy, typically in the form of light or heat.

In more detail, electrons exist in specific energy levels around the nucleus of an atom. These energy levels, also known as shells or orbits, are not arbitrary but are defined by the quantum mechanical model of the atom. Each energy level can hold a certain number of electrons and is associated with a specific amount of energy.

When an electron absorbs energy, it can 'jump' from a lower energy level to a higher one. This process is known as excitation. The energy absorbed is exactly equal to the difference in energy between the two levels. This energy can come from various sources, such as light (in the form of photons), heat, or a collision with another particle.

For example, if an atom is exposed to light of a certain frequency, the energy of the light can be absorbed by an electron. If the energy of the light photon matches the energy difference between the electron's current level and a higher level, the electron will absorb the energy and move to the higher level. This is why atoms can absorb light of certain frequencies and not others - the energy of the light must match an energy difference between levels.

On the other hand, when an electron 'falls' from a higher energy level to a lower one, it emits energy. This energy is usually released in the form of light, and the frequency of this light corresponds to the energy difference between the two levels. This is the principle behind many forms of light emission, including the glow of neon lights and the colours in fireworks.

In summary, the movement of electrons between energy levels is a fundamental process in physics and chemistry. It is driven by the absorption or emission of energy, and is responsible for many of the colours and forms of light we see in the world around us.